The race for this year's Air New Zealand Cup title intensified on Saturday with Bay of Plenty and Canterbury continuing to set the pace.

Chiefs rugby bragging rights reside firmly on the east side of the Kaimai Ranges after Air NZ Cup leaders Bay of Plenty outclassed Waikato 32-16 today.

In front of a bumper crowd at Mt Maunganui, first five-eighth Mike Delany inspired Bay of Plenty to a 32-16 victory over Waikato - their fourth successive win that condemned their neighbours to a third loss in the process.

The hosts were fortunate to be up 13-9 at half-time but played with authority and purpose after the break, allowing the deadly boot of Delany to seal the outcome. Not only did the 25-year-old land eight-from-eight shots at goal in a 22-point haul but he kicked well in general play and made some of the more telling breaks to continue his excellent form.

The last two penalties in the dying minutes were from halfway and the left touchline, both of which were nailed via Delany's three-step run-up, summing up the confidence and sweet timing that has marked his campaign.

Bay of Plenty scored two tries, including a brilliant team effort soon after half-time that put flanker Solomon King over following swift ball movement to both flanks of the field. Waikato centre Save Tokula got his side back to 16-23 down with half an hour remaining but errors marred their performance from there, expertly punished by Delany.

Canterbury finally cracked a tough Tasman nut with a 25-21 win which saw them keep the pressure on the Steamers.

In a tense Crusaders derby between the teams who came to Christchurch commanding positions two and three on the table, Canterbury clung to a narrow lead throughout the second half to record a third successive win.

Missing the majestic playmaking skills of Daniel Carter for the first time this season, Canterbury's standards of recent weeks dropped. Stand-in Stephen Brett produced some sporadic moments of brilliance in his place, including a classy 30m try in the 20th minute that pushed the hosts 17-6 clear.

However, they spent much of the rest of the match holding out a spirited Tasman. The visitors had the wood on a raw Canterbury pack, often bettering their scrum and disrupting lineout ball.

A powerful scrum on the half hour created the first of their two tries to impressive halfback Kahn Fotuali'i. When James Kamana crossed with half an hour remaining an upset was in the offing. However, the match nosedived into a scrappy affair and neither team scored again. Tasman had the consolation of snaring a bonus point and denying one to Canterbury, with the scoreline the closest they have come to an upset in the teams' four meetings.

Auckland produced their best performance of a flat campaign but it still wasn't enough to prevent a narrow 16-5 defeat to Wellington in what was also a Ranfurly Shield challenge match.

Auckland looked the more promising with ball in hand but Wellington were better at the basics after leading 8-3 at halftime in a tight contest. Wellington's third win in four outings this term came on the back of tries to prop John Schwalger and wing Hosea Gear, with Schwalger's effort in the 44th minute decisive.

It came after Gear attacked down the left flank before the ball was ferried to the far right where Schwalger found himself with enough open space to swan dive over the line. Auckland enjoyed their best patch of the match in the next 15 minutes but had nothing to show for it outside of a try to substitute fly-half Daniel Bowden.

The major talking point of the first half centred on referee Chris Pollock's decision to deny Wellington fly-half Fa'atonu Fili a legitimate try. Fili latched on to a loose ball, toed ahead and regather before grounding it over the tryline but Pollock and his two touch judges were unsighted. Pollock almost apologetically told Wellington captain that because the three officials were unsighted that he had no option other than to award the home side the feed to a 5m scrum.

With Westpac Stadium screen replays showing a try, the crowd was far from impressed but Pollock's hands were tied because competition rules do not allow match officials to review television footage.

Northland secured an excellent 26-23 away victory over North Harbour in the opening clash at North Harbour Stadium.

Despite struggling at the set-piece and spending much of the game defending in their own half they managed to conjure up just enough enterprising play to secure an unlikely victory.

It was a third successive loss for the home team and will be of huge disappointment to coaches Craig Dowd and Jeff Wilson after an impressive opening to the season which started with a win over Canterbury.

North Harbour were 3-10 down early on after Lachie Munro pulled the strings for the visitors scoring a try, conversion and a penalty but Harbour played well to regain the lead 16-10 at half time thanks to a try by Rudi Wulf and the boot of Michael Harris.

The second half saw Northland storm back into the game as they scored 20 unanswered points, the key moment coming from an intercept try by young Northland right wing Brook Gilmore.

The North Harbour lock Filo Paulo managed to burrow over with seven minutes remaining to lift his side within three points but they never threatened Northland again who held out for the win.

Both teams scored two tries while North Harbour's fly-half Harris and his Northland counterpart Munro were successful in all 11 kicks at goal between them. Munro was the outstanding performer for Northland as he scored 21 points including the first try in the 10th minute in a well executed move with fullback Jared Payne.

Northland hauled themselves up into mid-table while North Harbour remain perilously close to the foot of the table, third from bottom.

An impressive defensive display from Soutland saw them grind out an 18-9 victory over Hawke's Bay in Friday's other game - a result that lifted them to joint top spot with Manawatu.

A try by hooker David Hall shortly after the half-time break swung the game in the Stags' favour and they then stoically held out the visitors for a hard-fought win. Hawke's Bay held the lead 9-5 at the break thanks to Mathew Berquist who snapped over an early drop goal followed by two further penalties in response to a Josh Bekhuis try.

After the break and leading 12-9, Southland were finally able to put daylight between themselves and Hawke's Bay when fullback Robbie Robinson kicked a penalty. After withstanding a number of late surges from Hawke's Bay they were able to close-out the game by forcing a penalty on the halfway line which Robinson duly slotted.

The win for Southland is the third of their season while Hawke's Bay's loss follows their draw with Taranaki last week and they'll be desperate for a win against Tasman in the next round.

Manawatu maintained their strong start to the season with a 19-12 victory over Otago in Palmerston North on Thursday night.

Just a week after beating Southland by two points in Invercargill, Manawatu showed they are genuine play-off prospects with a solid all-round performance to see them go top of the table ahead of the rest of the weekend's fixtures.

After trailing 7-12 at half-time, Manawatu hit the front with two slick tries in the 10 minutes after the break that finished off the scoring for the match despite large amounts of Otago pressure that Manawatu impressively managed to absorb.

The game was not without controversy though, the major flashpoint being when their All Blacks flanker Adam Thomson claimed to have scored a try after his pack drove over - but referee Vinnie Munro couldn't see if the ball had been grounded.

Earlier, the Manawatu scrum-half Aaron Smith had been the hero when he got between the ball and the turf as former All Blacks prop Kees Meeuws crashed through the defence. Otago also paid for some poor handling, which undid much of their good work at the lineout, where they disrupted plenty of Manawatu ball.

After conceding a try to Stone in the fourth minute, Otago surged into the lead through tries to powerful winger Karne Hesketh and fullback Ben Smith but they were ultimately undone by their defensive lapses soon after the break, slumping to a third loss in their first four games of the campaign.

In the final game of the weekend, it was Counties-Manukau's "other winger" who supplied the spark as the struggling province lodged a joyous first win of their campaign in Pukehoe.

Left winger Sherwin Stowers outshone his teammate, All Blacks flyer Lelia Masaga, as a flat-footed Taranaki succumbed 33-21. Counties-Manukau were the only team without a win before this weekend but the team who most pundits have tipped to claim the wooden spoon made the most of their opportunities and played the more enterprising rugby.

Stowers featured heavily in the first two of their three tries, either side of halftime, which gave them breathing space. Another home-town hero was second five-eighth Tim Nanai-Williams, who slotted a penalty in the dying minutes for 18 points.

Taranaki, who drew 24-24 with Hawke's Bay last week, have been very inconsistent this season while Counties-Manukau produced one of the great bounce-backs, following last week's 51-15 hammering from Tasman.